Resilient wheel.



W. E. ROBERTSON..

RESILIENT WHEEL.

APPLICATION man Amma. 1914.

Patented Jan. 22, 1.918.

n s :nur onirica l WALTER E. ROBERTSON, F VENUS, TEXAS.

11,254,228, Specification of Lettera Patent) Patlgmtdl J 311m, 229 191g,Application led August 13, 1914. Serial No. 856,561.

To all wpom it may concern: bending regions' thereof; and to ermit a Beit known that I, WALTER E. ROBERTSON, too great freedom of movement of-te spring citizen of the United States, residing atso that the sameviolently vibrates or moves Venus, in the county of Johnson and Stateconvulsively, here, again, resulting in crys- 60 of Texas, have inventedcertain new and tallization, and causing the spring towaste usefulImprovements in Resilient Wheels, its energy in correcting or rightingitself to of which the following is a specilication. its normal expectedoperative association The present invention relates to improvewith theother wheel elements, instead of'bements in resilient wheels,4 and hasfor its ing immediately prepared to resist subset5. primary object theprovision of a wheel of quent shocks, etc., the result of which latter lthe character stated, and wherein the yieldis a severe conflict -offorces entirely frusable or adjustable, shock-absorbing and trating theharmonious action of the springs cushioning elements are located remotefrom necessary in a field of service, such as rapidly the hub, orspecifically within a rigid rim rotating vehicle wheels. 70 portion ofthe wheel, to the end that the y It has been with a view to meet andoverwheel-bearing and rigid spokes radiating come the foregoingobjections that I have therefrom may remain at all times inherconceivedthe construction (and utilized the ently relatively iXed or non-yieldingeleprinciples underlying the same) herein set ments, with respect towhich the rim-withforth, and which construction is, of course, 75 inwhich the outer ends of the said spokes merely one exempliication orembodiment Iare elastically suspended,-may bodily yield of my invention,it being clear to persons under the varying conditions incident toskilled in the art that the invention is caparoad travel to distributeand absorb throughble of incorporation in other forms and deout the rimcircumferentially thereof, the vices than that specilically disclosed.80 shocks flowing from undulating surfaces or The underlying idea of thespecific emobstructions'encountered by the periphery bodiment which Ihave elected to illustrate, lof the wheel. In this manner, the axle andas well as others as may be in keeping with iXed spokes may movesubstantially conthe hereto appended claims, involves, as

tinuously through a plane paralleling the previously stated, the use ofrigid spokes, 85 road surface, and in what might well be and meansresiliently suspending said said' to ,Y be a floating condition withinthe vspokes within a bodily displaceable rim self-adjusting rimsurrounding said rigid adapted to be engaged and steadied throughspokes.out and at all times by a coperating action The development of what isknownas the between the suspending means, and the in- 90 spring-wheelart, coupled lwith my per-v terior of the rim, so that while the rim maysonal observation and experimentation, covpromptly yield to accommodateobstructions, i ering a wide period of time, have demonand relativedepressions and elevations, in a strated the fact that perhapsinnumerable road bed, such yield will not be a loose or arrangements ofspring-members, including y tremulous movement, but will be more like a95 p 40 spring-spokes may be utilized in a wheel to rolling actionaround the ends of the spokes afford varying degrees .of elasticity,while within predetermined safety limits: and the rolling under acomparatively low speed, but yieldable suspension means being constimanyand great diiiculties present themtuted, in part, by uniform, bowedsprings, selves which must be overcome in1 aspringthe opposite terminalsof which are adapted l0@ wheel designed `to beoperated under high tospread and contract to afford a progresspeeds such' as must be expected.of wheels sively increasing seating engagement of the employed inconnection with motor vehicles. springs lengthwise thereof with adjacentAmong these diiiculties are the tendencies portions of and in the rim,and a correspondto exert severe end thrusts longitudinally of ingretraction of the springs away from 105 a spring leaf or member tendingto break or such seating engagement. rll`his action inshear itsfastening means; to create comsures the rim being held by the .springsat pound bending of elongated spring memapproximately all points aroundthe rim, bers, correspondingly increasing the reluc- 4no matter what thenature of its displacetance of the spring to restore itself speedilyment vertically or around the axis of the il@ to normal condition, andbyundue bending,- wheel, and the restoration of the rim to its tocrystallizeand break the spring in the initial or normal relation totheendsfof the fixed spokes being in an even, adual manner, asdistinguished from a su den or jerky movement, which latter wouldcorrespondingly transmitthe effect of its awkwardnss and jar to thevehicle body and occupants thereof.

My improved Wheel also utilizes the principle of yieldably suspendingthe load Within the rim in the line of and parallel to the line of theapplication of force applied to the rim. For example, the springsuspension is so formed, and the points of attachment of the springs soarranged, that throughout the circumference of the wheel the load isnormally supported by the yieldable resistance of the springsoifered insubstantially truly vertical planes, or at right angles to the roadsurface, whereas upon the encountering of an obstruction which willchange the point of application of pressure on the rim, the suspension'springs will automatically act to suspend the load in planes parallel tothe changed point of application of the force so that the rim is at alltimes, irrespective of the particular contact of eX- terior objects withits rim incident to the travel of the wheel, permitted to yield directlyaway from the obstruction, and to restore itself back to normal positionwithout requiring the overcoming of unnecessary or prohibitiveconflicting forces of springs not arranged to afford the continualparallel suspension to which I have alluded, andthe combating of whichlatter forces or resistance so often results in the shearing of thesprings, the crystallization or breaking thereof, and the impairment oftheir fastening devices, aside from the inconvenience and unsatisfactoryresults attending a tooyfree vibration` of the Wheel and incidentallythe vehicle body.

Another important advantage incident to my lconstruction is thefact-that while the rim is permitted to yield in various directionsaround the ends of the spokes, which yield'is permitted by means of theyspecial spring suspension devices employed in the combination, anypossibility of jar or shock which would iiowvfrom permitting a sharparound or over the ends ofthe spokes, Within the rim, and through theregion limited in an outward direction by a line intersecting theoutermost points of suspension of the suspension springs. This preventsthe springs being distorted or deflected beyond their elasticplimit.

The foregoing arrangement, preventing in the wheel per se an undesirableshock, jar, or tremulous action, correspondingly prevents the bouncingof the wheel and incidentally the vehicle proper, upon the surface ofthe road when meeting with rough surface conditions or obstructions onthe road surface, usually attending the use of a after passing the saidobstruction, and to.

hug the ground at all times so that a practically continuous tractionengagement 1s maintained, as distinguished from a vertical bouncing orjumping of the wheels andbody, when leaving the obstruction, asheretofore stated is so customary in the case of either rigidly mountedwheels or wheelsv provided with pneumatic tires, or relativelyunrestricted vibrating centers or points of an elastic suspension.

The forces of momentum and reaction of impact are utilized in this wheelas cushioning factors by shortening the radius between the outside ofthe rigid rim and inside of the center of the system, and by reason ofthe peculiar arrangement of the compensating members and points ofsuspension these two forces are permitted to pass each other withoutconflict.v y

Improved details and construction of parts will be clear from the morespecific description hereinafter contained, when read in connection withthe accompanying drawings forming part hereof, and wherein the preferredembodiment of the invention is illustrated.

In the drawings, A

Figure 1 is a side elevation of a wheel, parts being shown in section,made in keeping` with my invention,

Fig. 2 is a cross sectlonal view on the line wof Fig. 1,

Fig. 3 is a perspective view of the outerv end of one of the fixed orrigid spokes,

Fig. 4 is a detail sectional view showing the manner of attaching a pairof the springs to the rim, and

Fig. 5 is a detail sectional view through tion of said ends now j theside walls y.one of the buner rollers, and

aaaaare immediately associated parts.

Referring more specifically to the drawings, wherein like referencecharacters designate the same A represents the axle of a Wheel, B thehub adapted to constitute the bearing vfor a com,- plementary axle andcoperatin elements ordinarily combined with an ax e and not necessary tobe illustrated in detail herein, C indicating the customary dust cap.rllhe hub B, best seen in Fig. 2, is preferably of a two partconstruction, and conveniently of metal formation constructed integrallywith similar two-part spokes D of transversely curved construction torender the same rigid and of adequate strength, the spokes radiating.from the hub and being of proper number in consonance with standardwheel principles and requirements, the two parts of the spokes, andincidentally of the hub, being firmly united through the medium of boltslE.

llnasmuch as the outer ends 'of all of the spokes are alike, a detaildescription of one will suiiice for them all, the peculiar formato bedefined, being for advantageous purposes presently to appear. v

As clearly shown in lFig. 3, the end of the spoke is enlarged toconstitute a head F provided with a channel or opening runningtherethrough axially of the wheel to constitute a yoke G, havingparallel /side walls g radially of the wheel connected by a rounded baseg', said yoke presenting its open end toward the periphery of the wheel.Pro jecting outwardly from the parallel Walls gare two pairs of integralears H separated to provide spaces L therebetween bridged by pivot boltsor pins li. The ears are maintained in proper, spread relation bvspacing sleeves z', having their ends abutting the inner faces of theears and held agamstrotation by the impingement of said ends againstsuch faces under the clamping action of the bolts ll. Upon these spacingsleeves cylindrical bearing brasses j are sleeved, around which .oneterminal j of oppositely disposed springs l are secured to be free toturn or swing-'to a slight extent,

g of the yoke extending outwardly a substantial distance beyond thebolts ll4 to constitute reinforced backings or abutments y of thesprings.

Having now described what may be termed the relatively fixed portions ofthe wheel, namely, its hub and rlgid spokes, we may now further considerthe manner of suspending these spokes in the rim, which alsonecessitates a special consideration of the com onent parts of the rimitself, the latter belnga relatively displaceable or adjustable memberof the wheel and which,

parts in the several views, 4

2 for these terminals portionsA with the mounting of their resilientmeans therewithin, in connection with said rigid spokes, is the salientcharacteristic of my improvements.

For the sake of' convenience in assembling, the rim is formed 'of aplurality of segmental plates K adapted when brought into registration,to form circular side or face plates havinga closed periphery L formedby abutting inturned integral fia'nges on the plates and held togetherby bolts Z, said flanges being braced interiorly of the peripher and theplates being correspondingly lbraced and held in proper spaced relation,by a continuous reinforcing filler rin M, in turn held in place by theaforesai bolts Z.

Projecting outwardly from the plates K and joined therewithapproximately in line with the flanges L, are oppositely disposedtire-engaging and retaining flanges m adapted to gri a rubber or othercushion tire N.

rlhe filler ring or block M to which l above made mention, is scallopedon its inner face -to form a continuous series of seats or cradles Oaround the wheel, the side K, of course, being shaped to coliform tothis configuration, but projecting inwardly slightly beyond the surfaceof the scalloped face and ribbed as at p to embed in the opposite edgesof, and fasten in place, a friction retainer or guide P projectinginwardly beyond the innermost edges of the plates K, so as not to beinterfered with in its action by said plates. rlhis frictionalretaineror 'guide is preferably formed of ,rubber or lll@ yoke, normallyspaced therefrom at all points, is a rubber or equivalent buffer rollerR adapted to roll within the yoke when the rim is displaced under theactuation of the wheel, and adapted to limit the extent of displacementof the rim, such bufer roll being supported upon brackets r fastenedagainst the outer faces ofthe plates K and bythe bolts Z, which securethe plates in place, and with their inner ends projecting a substantialdistance radially inward beyond the ridge Q and the friction materialpassing threeover,-Fig. 1, the rolers R being immediately mounted inthese brackets, at the free or extended portions thereof, in a mannersimilar to the fastening of the spring terminals Fig. 4, that is, a boltr bridges the opening betweenY the brackets and bears a spacing sleever2 clamped belit@ tween the brackets by the action of the bolt in actingto hold the brackets in their desired spaced relation, and the rubberroller R having a tubular brass lining or bearing r3 adapted to revolveupon the spacing sleeve, as will be readily understood. It is needlessto show the several independent bea-rings employed in the wheel, becausetheir structure is the same in the various instances of the use. Theridge portions Q between any pair of cradles or seats O may be of someconsiderable breadth as shown, but the outer ridge portions S of eachpair,-or looking at it form another view point, those ridge portionsbetween the several pairs of cradles or seats,-are of greatly reducedcrossarea, or relatively narrow (Fig. l) for a purpose tobe pointed out.

At the opposite faces of the wheel, overlying the ends of the ridgeportions S, are

a pair of brackets T bolted in place as at t,

projecting inwardly radially beyond the ridges S and friction facingpassing thereover, and having a 'l' head t', in which the adjacent endsof a pair of the springs J are mounted in the same manner as themounting of the other ends of these springs, as hereinbefore discussedin connection with the headed ends of the spokes, and constituting thepoints of immediate suspension of the spokes in the rim.

Tn the case of both the brackets T and r, they are 4provided withenlarged outer ends or feet, as shown at U, to bear upon the tiregripping flanges m, whereby to better support the brackets againstoutward thrust, and the enlarged heads U are bolted at separated pointsas at u through the plates K, to better secure the adjacent segmentalplates against liability to open at their abutting edges.

By demonstration, T have found that to secure the most satisfactoryresults in the even distribution of forces around the rim of the wheel,and to prevent fracture or crystallization of the springs, the points ofsuspension of the spokesI within the rim should be arranged in an arcconcentric to the axisof the Wheel, that is to say, the bearings of anypair of the springs J at their points of connection with the end of thespoke and their opposite ends in the brackets T are all arranged to beintersected by a line constituting an arc of a circle drawn from thecenter of the wheel. By this arrangement, it follows that the move-'ment or displacement of the suspension means, Within the limits allowedby the combination of parts, while free within those limits, inconstantly within the rim, that is, outside of a straight-line drawn tointersect the` points of suspension for the outer ends of any two orpair of the springs J. This locates the ends of the fixed spokes-withinthe rim under all conditions of service and Latisana absolutely preventsany compound bending ing strip P, while the opposite terminals(connected to the headed ends ofthe spokes) extend away from saidfriction surface P to permit of the desired substantial play or`movement of the rim relative to the spokes to the degree circumscribedby the rubber buffers R. The result is that, as the wheel meets anobstruction and the rim is displaced and forced inwardly relative to therigid spokes, the lower springs are spread longitudinally, and in agradual progressive way, engage to increasing extents the retaining andguiding surfaces P, and commensurate with such engagement the strainsand forces are relieved from the pivotal points and engaged portions ofthe springs on the brackets T, and taken up directly by the rim properthrough the surface l), the latter gripping and guiding the springsthroughout their movement, and preventing any lateral slipping, e'. Qaxially of the wheel. Correspondingly the upper springs, tending to bowto a greater extent incident to the raising of the rim relative to theupper spoke ends, will exert a constant pressure periph.- erally ofthe'wheel to restore themselves to normal position, and as a consequentof such pressure the springs at said upper portion of the wheel willalso progressively engage the retaining and guiding surface, so that,all around the wheel the rim when displaced is not free to rebound witha jar or jerk, or to vibrate to any noticeableV extent, but is held inall of its positions throughout its periphery, and permitted toautomatically restore itself in an evenly balanced manner throughout theextent of the rim. Of course, the matter just considered deals primarilywith a blow to the rim truly radially thereof, but approximately thesame results How from any action on the rim tending to displace it,those movements of the rim other than truly radial, -being accommodatedand taken up by the springs in a rolling of the springs in theircradles, and the buffers R in their yokes at the ends of the spokes, thelatter, as already stated, serving the useful function of limiting themovement of the rim with reference to the xed spokes to such a degree aswill guarantee safety, an'd a permanent operating association of thedisplaceable rim with its fixed spokes.

The shape of the springs J is, as shown,

Langere proximates a U-tormation, but the branches or terminals are notsuliiciently long to ermit any compound or reverse curving o the spring,which compound or reverse curving has been found to prevent the use of are ends of the rigid spokes.

Many changes may be made in the details .of the construction hereinpointed out, as

may meet particular conditions governing special embodiments of myinvention, and while I have herein referred to my cradle and springformation as embodied and especially useful in a wheel, it is recognizedthat the same may be used in `other combinations, in which latterapplication or use l would not desire to be restricted other than as maybe required by the express terms of the hereto appended claims, or theequivalents thereof.

Having thus described the l claim is: f

l. Ar wheel 'liavingfrigid spokes, a disinvention, what l placeable rim,and resilient suspending means for the outer ends of the spokesconnected thereto at` points Within the said rim, said resilient meanscomprising oppositely disposed bowed vsprings connected at one end tothe outer'ends ot' the spokes and at the other end to a part of the rim,the rim having cradles upon which the springs may work,the ends ,of thesprings remote from the spokes being adapted to initially engage thecradle, and when placed under pressure to gradually and progressivelyincrease s uch engagement toward those ends of the springs connected tothe spokes, in combination with ridge portions on the rim intermediateof the cradles normally facing radially the ends ot' the spokes, andbuder members supported by the rim adjacent the said ridges, the saidends of the spokes constituting vokes adapted normally to be free fromsaid u'ers but under pressure to be engaged thereby.

2. A Wheel having rigid spokes, a displaceable i-im, and resilientsuspending means for the outer ends of the spokes connected thereto atpoints Within the said rim 'said resilient means comprising oppoi sitelydisposed bowed springs connected at one end to the outer ends of thespokes and at the other end to a part of the rim, the

rim having cradles upon which the springs may work, said cradles havingretaining and guiding means on the inner face thereof for the saidsprings, the ends of the springs remote from the spokes being adapted toinitially engage the retaining and guiding means and when placed underpressure to gradually and progressively increase such engagement towardthose ends of the springs connected to the spokes, in combination withridge portions on the rim intermediate of the cradles normally facingVradially 'the ends of the spokes, and buer members supported by the rimadjacent the said ridges, the said ends of the spokes constituting yokesadapted to be normally free from said buierslout under pressure to beengaged thereby.

3. A Wheel having rigid spokes, a displaceable rim, and resilientsuspending means for the outer ends of the spokes connected ythereto atpoints Within the said rim, said resilientl means comprising oppositelydisposed bowed springs connected at one lend to the outer ends of thespokes and at the other end to a part of the rim, the rim having cradlesupon Which the springs may Work, the ends of the springsV remote fromthe spokes being adapted to initially engage the cradle, and When placedunder pressure to gradually and progressively increasesuch engagementtoward those ends of the springs connected to the spokes, in combinationwith louder members supported by the rim at points intermediate of thecradles, and normally arranged radially in line With the ends of thespokes, said ends of the spokes constituting yokes adapted normally tobe free from said buffers but under pressure to be engaged thereby.

4i. A Wheel having rigid spokes, a displaceable rim, and resilientsuspending means for the outer ends of the spokes -connected thereto atpoints Within the said rim, said resilient meanscomprising oppositelydisposed bowed' springs connected at one end to the outer ends of thespokes and at the other end to a part of the rim, the rim having cradlesupon which the springs may Work, said cradles having retaining andguiding means on the in ner face thereof for the said springs, the endsof the `springs remote from the spokes being adapted to y initiallyengage the retaining and guiding means and when placed under pressure togradually and progressively increase such engagement toward those endsof the springs connected to the spokes, in combination with buli'ermembers supported by the rim at points intermediate of the cradles, andnormally arranged radially in line with the ends of the spokes, saidends of the spokes constituting yokes adapted normally to be free fromsaid buti'ers but under pressure to be engaged thereby.

5. A wheel having rigid spokes, a displaceable rim, and resilientsuspending means for the outer ends of the'spokes connected thereto atpoints within the said rim, Said resilient means comprising oppositelydisposed bowed springs connected at one end t0 the outer ends o'f thespokes and at' the other end to a part of the trim, the rim havingcradles upon which the springs may work, the ends of the springs remotefrom the spokes being adapted to initially engage the cradle, and whenplaced under pressure to gradually and progressively increase suchengagement toward those ends of the springs connected to the spokes, incombination with elastic bilder rollers supported by the rim at pointsintermediate ofthe cradles, and normally arranged ruadially'in line withthe ends of the spokes, said ends of the spokes constituting yokesadapted normally to be free from said buffers but under pressure to beengaged thereby.

6. A wheel having rigid spokes, a displaceable rim, and resilientsuspending means for the outer ends of the spokes connected thereto atpoints withinlthe said rim, said resilient means comprising oppositelydisposed bowed springs connected at one end t0 the outer ends of thespokes and at the other end to a part of the rim, the rim having cradlesupon which the springs may work, said cradles having retaining and'guiding means on the inner face thereof for the said springs, the endsof the springs remote from the spokes being adapted to initially engagethe retaining and guiding .means and when placed under pressure togradually and progressively increase such engagement toward those endsof the springs connected to the spokes, in combination with elasticbuffer rollers supported by the rim at points intermediate of thecradles, and normally arranged radially in line with the ends of thespokes, said ends of the 'spokes constituting yokes adapted normally tobe free from said buffers but under pressure to be engaged thereby.

7. A wheel having a. hub, spokes, rim, and resilient means for engagingthe outer ends of the spokes permitting displacement of the rim relativeto the spokes, said means including a pair of spaced members, a boltbridging'the space between said members, a spacing sleeve held in placewith its ends engaging the inner faces of said members by said bolt, anda rotatable bearing on said spacing sleeve.

8. A wheel having rigid spokes, a rim, and

resilient suspending means for the outerends of the spokes connectedthereto and to parts of the rim, said means 'including 0ppositelydisposed bowed springs, and cradles formed in the rim arranged so thatpressure applied at any of the springs will distribute the force ofimpact throughout the other springsaround the rim by effecting anincreasing surface engagement of the springs Laegaaa with theirrespective cradles, in combination with abutting portions disposedbetween the springs arranged to contact under abnormal pressure with theends of the spokes.

9. A wheel having rigid spokes formed with yokes at their outer ends, arim, abutments on the rim adapted to engage the outer ends of the spokesunder abnormal displacement of the rim, and yieldable suspension devicesin the rim for said spokes connected to the rim and to the spokes topermit a rolling action of the rim within the said yokes, substantiallyas described.

10. A Wheel having rigid spokes formed with yokes at their outer ends, arim, roller means in said cradles, oppositely disposed bowed springsconnected at one en'd to parts of the rim and at their other ends to theendsof the spokes, and butter members on the rim intermediate of saidcradles normally free from but adapted to engage the surface of saidyokes.

12. A wheel having a hub and rigid spokes provided with yokes at theirouter ends, a rim having a scalloped inner surface constituting cradles,retaining and guiding means in said cradles, oppositely disposed bowedsprings connected at one end to parts of the rim and at their other endsto the ends of the spokes, and buffer members on the rim intermediateof'said cradles normally free from but adapted to engage the surface ofsaid yokes, the points'of suspension of the springs being in an arcconcentric to the axis of the wheel.

13. A wheel having a hub and rigid Spokes provided with yokes at theirouter ends, a rimhaving a scalloped inner surface constituting cradles,retaining and guiding means in said cradles, oppositely disposed bowedsprings connected at one end to parts of the rim and at their other endsto the ends of the spokes, and buffer members on the rim intermediate ofsaid cradles nor 120 mally free from but adapted to engage Ithe surfaceof said yokes, the points of suspension of the springs being 1n an arcconcentric to the axis of the wheel, and the springs being arranged toinitially engage the re- 125 14. A wheel having a hub and rigid spokesprovided with yokes at their outer endsa rim having a scalloped innersurface constituting cradles, retaining and guiding means in saidcradles, oppositcly disposed bowed springs connected at one end to partsof the rim and at their other ends to the ends of the spokes, and buffermembers on the rim intermediate of said cradles normally free from butadapted to engage the surface of said yokes, the points of suspension ofthesprings being in an arc concentric to the axis of the wheel, and thesprings being arranged to initially engage the retaining and guidingmeans adjacent to their point of attachment to the rim and toprogressively increase such engagement along the spring as increasedpressure is applied to the rim, the spokes being provided withreinforcing projections adjacent to the yoke portions thereof to back upthe end portions of the springs.

15. In a resilient vehicle wheel, the combination lwith a hub, and spokemembers radiating fromuthe hub, of springs extending from the outer endsof the spoke members, said springs being curved from the spoke membersand having their outer ends connected in pairs, a rim surrounding thespoke members and having recesses shaped to receive the springs whichnormally stand out of the recesses, members rigidly connectin@ the'connected ends of the springs with talle rim, and buffer rollers carriedby the rim and positioned between the springs at their points ofconnection with the spoke members.

16. In a vehicle wheel, means for yieldably suspending a part thereofcomprising a pair of curved cradles, an opposing rigid member toward andfrom which the cradles move, and bowed springs connected at one end tosaid rigid member and at the opposite end to parts attached to thecradles, said springs being arranged to engage in a gradually increasingsurface contact lengthwise thereof with the cradles, in combination witha buffer member arranged intermediate of the cradle and adapted tocontact and play over the end of the fixed member.

`17. ln a vehicle wheel, means for yield- 'ably suspending a partthereof comprising` a pair of curved cradles, an opposing rigid membertoward and from which the cradles move, and bowed springs connected atone end to said rigid member and at `the opposite end to parts attachedto the cradles, said springs being arranged to engage in a graduallyincreasing surface Contact lengthwise thereof with the cradles, the endof the fixed member being located within a plane bounded by alineintersecting the outermost points of suspension of the spring, in

combination with a buffer member arranged intermediate of the cradlesand adapted to contact and play over the end of the fixed member.

ln testimony whereof l afliX my signature in presence of two witnesses.

WALTER E. ROBERTSUN. Witnesses f:

H. N. RAMSEY, E. F. Rim.

